Positive two-hand control



F. W. SAUERBREY POSITIVE TWO-HAND CONTROL 2 Sheets-Sheet 1 June 6, 1933.

Filed Aug. 1,1930

ORNEYS June 6, 1933. F. w. SAUERBREY 1,912,861

POS ITIVE TWO-HAND CONTROL Filed Aug. 1, 1950 2 Sheets-Sheet 2 BY? %}ENT?R. My

- ATTORNEYS.

- element or buck 15 supported on a neck 16 Patented June 6, 1933 UNITED STATES PATENT OFFICE FREDERICK W. SAUERBREY, 0F SYRACUSE, NEW YORK, ASSIGN'OR TO THE PROSPERITY COMPANY INC., 011 SYRACUSE, NEW YORK, A CORPORATION OF NEW YORK rosrrrvn. Two-HAND co'umor.

Application filed August 1, 1930. Serial No. 472,334.

This invention relates to pressing machines and particularly to two-hand control means for operating such machines.

Numerous two-hand control devices have been devised for use on pressing machines. With such control devices in the past, it has been possible to operate the press by using only one of the controls if the other control should become stuck in operated position, or should be tied down in such position by the operator.

The principal object of this invention is to v devise a two-hand control for a pressing machine motor, such control being designed so that it is necessary for both control devices to be used to perform each opening and closing operation of the press.

A further object of the invention is to devise a two-hand control which can not be operated'to control the pressing machine motor if one of the control devices becomes stuck in operated position, or should be tied down in such position by the operator.

Other objects and advantages of the invention will be pointed out and will become apparent as the description proceeds.

, The invention consists'in the. novelfeatures and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

.Figure 1 is a side elevation of a pressing machine to which my invention is applied.

Figure 2 is a schematic showing, -mostly in section, of the press operating motor and the two-hand control means for the motor.

The invention is designed primarily for use on pressing machines having an opening and closing movement.

Such amachine is shown in Figure 1 and includes a pressing head 10 secured to ayoke 11 which is mounted at 12 on a'frame 13 of the pressing machine. The head 10 moves into and out of contact with a fixed pressing which is mounted on the pressing machine frame 13. The yoke 11 is oscillated about its pivotal connection 12 by a link 18 which is connected at its upper end at 19 to the yoke 11 and at its lower end at 20 to a bell crank 21. The bell crank 21 is pivoted at 22 to the pressing machine frame 13.

A fluid motor 25 is oscillatedly mounted at 26 on the pressing machine frame 13 and includes a piston rod 28 which is pivotally connected at 30 to the bell crank 21. The link 18 and upstanding arm of the bell crank 21 form a toggle and the fluid motor 25 oscillates the bell crank 21 about its pivotal connection 22 to break and straighten the toggle to open and close the press. A spring 33, which is connected at its upper end to the pressing machine frame 13 and at its lower end to the bell crank 21, normally holds the press in open position. The structure thus far described is of the conventional type well understood by those skilled in the art and forms no part of having a piston 36 therein which is rigidly mounted on the connecting rod 28. A port 38 is provided in the cylinder wall near the lower end thereof and this port 38 opens into a chamber 39 which connects through an orifice 40 with a pipe 41.

The upper end' of the cylinder is provided with a conduit 44 having branches 45 and 46 which lead to the valve casings 48 and 49 respectively.

The valve casing 48 contains a. normally closed intake valve 50 and a normally open exhaust valve 51 which are connected together by a spacer rod 52 so that the valves operate as a unit. A spring 53 holds the valves 50 and 51 in their normal position. The exhaust valve 51 is provided with a valve stem 55which projects through the end of the valve casing 48 and is operated by a rocker arm 56 to move the valves 50 and 51 against the tension of the spring 53, to open the intake valve 50 and close the exhaust valve 51. The rocker arm 56 is pivoted at 58 to a bracket 59 formed on the valve casing 48.

A push button 60 operates a bell crank 61 which is pivoted at 62 to the pressing machine frame 13. One arm of the bell crank 61 contactslwith the push button 60 and the Depression of the push button by an operator will move the bell crank 61 to operate the rocker arm 56 to move the valves 50 and 51, in the valve casing 48, into operated position.

The valves 50 and 51, in the valve casing 48, may be locked in operated position by a plunger 64 which projects through the end of a diaphragm chamber 65 containing a diaphragm 66. Pressure applied behind the diaphragm 66 will cause the diaphragm to move the plunger 64 to the left in Figure 2 to hold the rocker arm 56 and the valves and 51, in the valve casing 48, in operated position.

The valve casing 49 contains a normally closed intake valve 68 and a normally open exhaust valve 69 which are connected together by a spacer rod 70 so that they oper-v ate as a unit. A spring 71 holds the valves 68 and 69 in normal position. The exhaust valve 69 is provided with a stem 72 which projects through the end of the valve casing 49. A rocker arm 76 is pivoted at 78 to a bracket 79 formed on the valve casing 49. A push button 80 is provided which operates a bell crank 81. The bell crank 81 is pivoted at 82 to the pressing machine frame 13. When the operator depresses the push button 80 the motion will be transmitted through the bell crank 81 to the rocker arm 76 to operate the valves 68 and 69 in the valve casing 49. The valves 68 and 69 may be held in operated position by aplunger 84 which pro jects through the end of a diaphragm chamber 85 containing a diaphragm 86. When pressure is applied behind the diaphragm 86 the plunger 84 will be moved to the left in Figure 2 to hold the rocker arm 76 and valves 68 and 69, in the valve casing 49, in operated position. Working fluid is supplied to the valve casings 48 and 49 from a suitable source such as a supply line 90 having a branch pipe 91 which leads to the valve casing 48, and a branch pipe 92 which leads to the valve casing 49.

The diaphragm chambers 65 and 85 are connected by pipes 95 and 96 respectively with the pipe 41 which communicates with the port opening 38 in the wall of the cylinder 35.

An exhaust valve 100 is provided in a valve casing 101 and this exhaust valve is normally held in closed position by a spring 102. A handle 104, which contacts with thevalve stem 105 of the exhaust valve 100, may be operated to open the valve'lOO to permit working fluid to escape from the pipe 96 through a pipe 107.

The operation of the device isas follows With the parts in the positionsshown in Figure 2 the press will be in open position since the piston 36 and piston rod 28 are at the top of their stroke. Working fluid from the fluid supply source 90 will ass through the branch pipes 91 and 92 to t e valve casings 48 and 49 respectively, but will not flow past the closed intake valves 50 and 68 re-' spectively.

If the operator depresses the push but ton 60, but does not depress the push button 80, working fluid will flow from the source 90, through the branch pipe 91, around the open intake valve 50, through the valve casing 48, and pipe 45 to the conduit 44 which supplies working fluid to the motor. No pressure will build up in the pipe 45 or conduit 44 however, since the working fluid will escape throughthe pipe 46, valve casing 49, and open exhaust valve 69. Thus it is impossible to operate the fluid motor 25 by depression of the push button alone.

In like manner operation of the push button 80, when the push button 60 is in normal position, will not operate the fluid motor 25. Working fluid from the source 90 will flow through the pipe 92 around the open intake valve 68, through the valve casing 49, and pipe 46 to the conduit 44, but no pressure will build up in the pipe 46 or conduit 44 since the working fluid is free to escape through the pipe 45, valve casing 48, and open exhaust valve 51. i

From the above description it is obvious that the operator must depress both of the push buttons 60 and 80 in order to operate the fluid motor 25 to close the press. When both of the push buttons 60 and 80 are operated at the same time working fluid will be supplied through the pipes 45 and 46 to the conduit 44 as will be readily understood from, the foregoing description.

As the piston 36 moves downwardly in the cylinder it will uncover the port 38 which is located in such a position that the piston 36 will pass it just as the pressing elements come together and there is no longer any possibility that the operator may place one hand between the pressing elements. When the piston 36 uncovers the port 38 working fluid will flow through the port 38, through chamber 39, orifice 40, pipe 41, and branch pipes 95 and 96 to the diaphragm chambers and 85 respectively to operate the diaphragms therein and lock the valves in the valve casings 48 and 49 respectively in operated position. The operator may then remove his hands from the push buttons 60 and 80 and the press operating mechanism will continue to move to put the pressing elements under heavy pressure and lock the press in closed position.

When the operator wishes to 'open the press he will actuate the handle 104 to open the exhaust valve 100 in the valve casing 101 and permit working fluid to escape from the plpe 41 and branch pipe 95 through the branch plpe 96, and pipe 107. Since air can not flow rom the chamber 39 through the orifice as fast as it can exhaust through the pipes 95,96 and 107, and open exhaust valve 100, pressure will drop in the diaphragm chambers 65 and 85 and the springs 53 and 71 will move the'valves in the valve casings 48 and 49 respectively into normal osition. When the valves in the valve caslngs 48 and 49 are restored to normal position the supply of working fluid from the source 90, through the branch pipes 91 and 92 is cut off by the closed intake valves 50 and 68 respectively. Working fluid will exhaust from the cylinder 35 through the conduit 44 and branch pipes 45 and 46 to their respective valve casings 48 and 49, and through the open exhaust valves 51 and 69.

With my two-hand control mechanisms it may not be possible to exhaust working fluid from the motor even though one of the control devices remains in operated position because the control device may have been'designed and constructed with an exhaust port of such size that two such ports, one in each control means, are necessary to exhaust the pressure from the motor. The fluid supply maybe able to furnish a greater volume of air or fluid than can escape through one port of limited size and in such case fluid pressure would remain upon the motor to hold the press closed. In such case, it should be noted that the press will not open if the valves in either of the valve casings 48 or 49 remain in operated position. For example, if the valves in the valve casing 48 should be stuck in operated position, or if the push button 60 should betied down, so that the valve 50 remained open and the valve 51 remained closed after pressure in the diaphragm chamber 65 had been reduced, working fluid would continue to flow from the v source90, through the branch pipe 91, around the open intake valve 50, through the valve casing 48 and pipe 45 and out of the open exhaust port in thecasin 49. Even though the exhaustvalve 69 wou d be open the supply of working fluid through the pipe 45 may be greater than the exhaust of working fluid through the open port and hence will prevent the exhaust of working fluid from the cylinder 35 through the conduit 44.

Even if working fluid escapes through the pipe 46, valve casing 49, and open exhaust valve 69, faster than it is supplied through the pipe 45 thus permitting exhaust from the cylinder 35,'through the conduit 44, this exhaust will be very slow and the operation of the press correspondingly slow, in' opening and hence entirely unsatisfactory. Since the only reason why the operator would want to tie down one of the control means or valves would be to gain speed through one-hand operation of the press, the gain is entirely lost through the very slow opening of the press. It will therefore be necessary for the operator to repair the press by rendering the valves in the valve casing 48 again operative thus restoring the two-hand control safety feature.

The operating mechanism described for operating the press includes an operating motor which is normally connected with exhaust to air or to a zero pressure. The operating motor is connected with a power supply through two parallel branches in that each connection is connected with a source of power which may be the same source for each branch. Power control means or devices are. provided in each branch of the connection with the motor and each control means is operable to connect the operating motor with the power supply. Normally each control means connects the operating motor with the exhaust, such as atmosphere or zero pressure, and upon operation of the control means to connect the opeating motor with the source of power supply, the exhaust or zero pressure connection with the motor is simultaneously disconnected. If, therefore, only one control means is operated or actuated, the source of power supply is connected to exhaust or zero pressure through the other control means and the operating motor does not get any or at least sufficient power or pressure to operate. In order to'obtain suflicient power or pressure, both control means must be operated. Again, it is not possible to tie one ofthe control means in operated position and attempt to operate the press by actuation of the other control means since in that case the power supply would be directly connected with the exhaust or zero pressure at the control means in the other power supply branch. This would soon deplete or terminate the power supply and the operator must untie or fix the control means which is held inoperative position."

From the above description it will be ape l parent that I have devised a two-hand control mechanism which is positive in that it is necessary to operate both of the control devices for each opening and closing movement of the press, and it is impossible to satisfactorily operate the press it one of the com trol devices become stuck in operated position or is held in operated position purposely by tampering with the control mechanism, as for example by tying apush button in depressed position. The invention is illustrated in its preferred embodiment, but

changes and modifications may be made without departing from the spirit of the invention as set forth in the appended claims.

What I claim is:

1. In a pressing machine an operating motor and a two hand control therefor including a fluid supply conduit means connected with the motor and having two branches; each branch having a normally open exhaust opening, fluid supply control means located in each of said branches, each control meansbeing operable to admit working fluid to its respective branch of the fluid supply conduit and to simultaneously close the exhaust opening for said fluid supply conduit; and conduits connecting each of the fluid supply control means with a source of working fluid.

2. In a pressing machine in combination a fluid motor; a conduit through which the working fluid may be supplied tothe motor; a pair of devices each having an exhaust normally connected with the motor and controlling the flow of working fluid through the conduit, either of the control devices operable in one position to admit working fluid to the conduit exhaust for working fluid from the motor, the control devices being operable in the other position to open the exhaust for working fluid from the conduit and close the connection for fluid supply; means normally holding the control devices in exhaust position; and a working fluid supply line connecting the control devices in parallel with a source of working fluid.

3. In a pressing machine in combination a fluid motor; a conduit through which working fluid may be supplied to the motor; a pair of independently operable devices to control the flow of working fluid through the conduit; each device having a normally open exhaust connected with the motor; operatoroperated means for each control device to actuate the same into position to admit working fluid to the conduit and simultaneously close the exhaust; means for returning each control device to normal position to open the exhaust for working fluid from the conduit; and independent fluid supply lines connected to each of the control devices.

4. Ina pressing machine in combination a fluid motor; a conduit through which working fluid flows .to and from the motor; a pair of valve means for controlling the flow of working fluid through the conduit; conduit means connecting the valve means in parallel to a source of working fluid; and exhaust port in each valve means connected with themotor; means normally holding each of the valve means in position so as to open the exhaust port for the conduit; operator-operated devices for actuating ea h of the valve means into position to close the exhaust port therein and simultaneously establish communica-;

tion between the working fluid connection and the conduit for supplying working fluid to the motor.

5. In a pressing machine in combination a fluid motor; a conduit through which working fluid flows to and from the motor; a pair of valve means for controlling the flow of working fluid through the conduit, each of said valve means including a normally open exhaust valve and a normally closed intake valve; an independent connection between each of the valve means and a source of working fluid operator-operated means associated and simultaneously closing the I with each valve means for actuating the same to close the exhaust valve and simultaneously open the intake valve so that working fluid may flow from the working nection to the conduit for supplying working fluid to the motor.

6. In a pressingmachine in combination a fluid motor; a conduit through which working fluid may flow to and from the motor; two branches in said conduit; connected at the ends of said branches; a fluid supply line connecting each of the valve casin s independently with a source of working uid; valve means in each of the valve casings, said valve means including a normally open exhaust valve, through which Working fluid from the conduit may exhaust, and a normally closed intake valve; operatoroperated means for simultaneously actuating the valves in each valve casing to close the exhaust and simultaneously open the intake valve so that when the valves in both valve casings are operated working fluid from the fluid supply connection will flow through the conduit to the motor.

7. In a pressing machine cooperative pressing elements one of which is movable toward and from the other; press operating mechanism for the movable pressing element including a fluid motor; two-hand control means for controlling the supply of working fluid to the motor, said control means including a pair of valve-means having an exhaust normally in position to permit the exhaust of working fluid from the motor; conduit means connecting the valve means to'the motor, said conduit means including branches running to each of the valve means; an independent connection between each of the valve means and a source of working fluid; operator-actuated devices for operating each of the valve means into position to supply working fluid to the motor and simultaneously close the exhaust; and means operated from the press operating mechanism to lock the valve means in operated position when the pressing elements come together to close the press.

8. In a pressing machine cooperative pressing elements one of which is movable toward and from the otherpress operating mechanism for the movable pressing element including a fluid motor; two-hand control mechanism for the fluid motor including a pair ofvalve'casings; a conduit for working fluid to the motor formed With branches running to each of the valve casings; a connection between each and a*source of working fluid valves in each of the valve casings including a. normally closeil'intake valve, and a normally open exhaust valve through which working fluid mayexhaust from the conduit; operator actuated devices for operating the valves in each of the valve casings to close the exhaust fluid source convalve casings of the valve casings valve and simultaneously open the intake valve .so that working fluid from the connection with the source of working fluid may flow through the valve casing to the conduit for working fluid to the motor; and means operated by working fluid from the motor for locking the valves in operated position when the pressing elements come together to close the press.

9. In a pressing machine an operating mechanism including an operating motor to close the press and normally having a zero pressure connection, means to open the press upon release of power to the operating motor, a two-hand control for the operating motor including a power supply-line'connected with the motor and having two branches, power control means in each of said branches and spaced from eachother, each control means being operable to connect the motor through its respective branch to the power supply line and to simultaneously disconnect the motor from a zero pressure connection, and means connecting each of the power supply control means with a source of power.

10. In a pressing machine an operating mechanism including an operating motor to close the press and normally having a zero pressure connection, means to open the press upon release of power to the operating motor, a two-hand control for the operating motor including a power supply line connected with the motor and having two branches, power control means in each of said branches and spaced from each other, each control means being operable to connect the motor through its respective branch to the power supply line and to simultaneously disconnect the motor from a zero pressure connection, means connecting each of the power supply control means with a source of power, and means operated from the press operating mechanism to lock the control means in operated position when the pressing elements come together to close the press.

In testimony whereof, I have hereunto signed my name, at Syracuse, in the county of Onondaga, and State of New York, this 24th day of July, 1930.

FREDERICK W. SAUERBREY. 

